Keston Combi C45 boiler low flow rate

Hello Folks,

I have a Keston Combi C45 boiler, which is about four years old, & it is always serviced annually. Well, currently I am here to share my problem basically; the flow rate of the hot water is terrible. I am not sure what is wrong with the boiler. Is this merely a fault with boiler’s DHW blocking due to limescale with the passage of time? Alternatively, could it be anything else. Please help



Hi Joe, you are facing this issue due to the following reasons:

  • Jammed filter
  • Restricted pipework
  • Spearing jumper in the stop
  • Mains stopcock
  • Bad mains pressure

You can try the following ways out:

  • Clean the jammed filter
  • For restricted pipework, you can use a pipework with larger diameter
  • Replace the valve
  • For the mains stopcock, try operating or replacing the stopcock
  • Lastly, if you notice poor or reduced mains pressure then, do examine that each arrow on the stopcocks is going in the direction of water flow.